Mercedes-Benz is using augmented reality to help first responders rescue people from cars more quickly. The Rescue Assist app displays schematics of vehicles on a smartphone or tablet, allowing rescuers to plot the quickest and safest way to extricate crash victims.

The app overlays vehicle information on the view from a device’s camera, so users just need to hold the device in front of a car to see what’s inside. All of a vehicle’s systems and hardware are displayed as a 3D model. That allows first responders to to locate things like fuel lines, the high-voltage cables in electric cars and hybrids, and airbags that may not have deployed.

Knowing where these components are makes it easier for first responders to plot where to cut into a vehicle in order to free trapped passengers, Mercedes says. It’s probably a good idea to know where the combustible fuel and electricity are before cutting open a car, after all. The 3D images allow users can zoom in and rotate to get the clearest view possible.

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The app is an expansion of the existing Rescue Assist program, which allows users to view static vehicle schematics online. Mercedes says it can function without an internet or cellular connection. The app comes preloaded with schematics for every Mercedes passenger car built after 1990, every Mercedes van built after 1996, and every Smart car built since the brand’s launch in 1998. Schematics for certain Fuso commercial trucks are included as well. The app is available for iOS and Android, in 24 languages.

To identify a vehicle, the app reads a QR code on the B-pillar or fuel-filler door. Every new Mercedes, Smart, and Fuso vehicle has these QR codes, but owners of older models must take them to dealers to get code stickers. A big part of the app’s effectiveness depends on whether they will take the time to do that.